Grate driving means for incinerators



Dec. 13, 1960 B. F. SHAUGHNESSY 2,954,035

CRATE DRIVING MEANS FOR INCINERATORS 3 Sheets-Sheet 1 Filed March 15, 1957 v ww INVENTOR.

4b is a rv-aleh/ar Dec. 13, 1960 B. F. SHAUGHNESSY GRATE DRIVING MEANS FOR INCINERATORS Filed March 15, 1957 3 Sheets-Sheet 2 III BYZ' 6 g a r rag/Jay Dec. 13, 1960 B. F. SHAUGHNESSY 2,964,035

GRATE DRIVING MEANS FOR INCINEIRATORS Filed March 15, 1957 5 Sheets-Sheet 3 asp/W120 E Sum/aw: as

United States Patent GRAIE DRIVING MEANS ron INCINERATORS Bernard F. Shaughnessy, 417 Pine St., Lehigh County,

Catasauqua, Pa.; Helen R. Shauglmessy, executrix of said Bernard F. Shaughnessy, deceased Filed Mar. 15, 1957, Ser. No. 646,260

2 Claims. (Cl. 126-169) My invention relates to incinerators and more particularly to those of the type employed in burning rubbish and other waste materials.

One object of the invention is to provide, in an incinerator apparatus of large capacity wherein the grate is rotated in a horizontal plane, together with means for deenergizing the driving motor, or reducing the power thereof, when an overload condition occurs in the incinerator.

Some of the forms which my invention may take are shown in the accompanying drawings wherein:

Figure l is a vertical sectional view through a portion of an incinerator apparatus.

Fig. 2 is a plan view of the grid for supporting the grate of Fig. 1.

Fig. 3 is an enlarged vertical sectional view showing a yieldable drive for rotating the grate and for automatically disconnecting an electric motor that drives the grate.

Fig. 4 is a face view of the device of Fig. 3.

Fig. 5 shows a modification of the safety driving mechanism of Figs. 3 and 4; Fig. 6 is an end view of the apparatus of Fig. 5 applied to a furnace.

Figure l is a vertical sectional view, showing a rotating grate 24 and one form of driving mechanism therefor. The framework or housing contains a pit room 20 and an ash receiving space 21. The grate bars are supported on rings 25 and 26, that are in turn supported by grid members 27 that are shown in plan in Fig. 2. A central refractory block 28 is also carried by the grid members 27.

The grate structure is rotatable and has secured to the underside of the frame members 27 a circular rack 30 that is driven by a pinion 31. The grid 27 and the grate carried thereby, are supported by rollers 32 which are rotatable on shafts 33 (Fig. 1) that are adjustably clamped in the rigid frame work of the machine by U-bolts 34. The rollers 32 are flanged to hold the rotating table against displacement, and thrust bearings 35 are provided between the rollers and the inner ends of their shafts 33. An annular sealing ring 36 is positioned on the grate 24 to prevent ashes and rubbish from falling down past the outer edge of the rotating table.

The table of Fig. 1 is rotated by an electric motor 38, operating through a transmission mechanism at 39, that includes a pinion 40, a sprocket chain 41, a sprocket wheel 42, a shaft 43 and the pinion 31.

An important feature of my invention resides in the provision of a flexible drive that rotates the grate. As shown in Figs. 3 and 4, the driving member 40 has stop shoulders 40b therein. A driven member 42 is set within the driving member 40 and has spoke-like extensions 43 that are positioned in opposed relation to the stop shoulders 40b, coil springs 44 being interposed between the members 40b and 43, so that there will be a yieldable drive for the grate. This is important, because it is desired that the machinery be automatically stopped in case of jamming by tramp iron, or by a hardened lump or Patented Dec. 13, 1960 mass of material such as heat-softened silica that has later congealed and become adhered to the wall of the furnace in such position as to obstruct rotation of the grate. This automatic stop is a safety precaution against disruption of the mechanism or damage to the furnace wall.

The motor 38 is controlled from an electric switch 46. The driving member 40 is rigidly mounted upon a shaft 47 on which the driven member 42 is loosely mounted. When an obstruction is encountered in the furnace, the springs 44 will be compressed more greatly and the driving member 40 will be driven somewhat further on the shaft, relative to the driven member 42. This will result in a camming collar 48 being forced against a collar 49 in opposition to a spring 50. Thereby a lever 51 is released for movement about its pivot 52, by pressure of a spring 53, thus tripping the switch member 46 and allowing it to open and break the cricuit through the conductors 54 to the motor 38. When the driving mechanism for the grate has been stopped through an overload or the like as above described, the obstruction will of course, be removed before resetting the switch mechanism to close the motor circuit.

A modification of the control device of Fig. 3 is shown in Figs. 5 and 6 wherein the shaft 56 that corresponds to the shaft 43 of Fig. l, for rotating the table, is driven by a sprocket Wheel 57 that corresponds to the driver 40, and a driven member 58 that corresponds to the member 42 of Fig. 4, springs corresponding to springs 44 being interposed between 57 and 58. However, instead of providing a camming device similar to the member 48 of Fig. 3, I provide a tensioning device that comprises a spring 60 whose tension is adjustable by a handwheel 61. A cable 62 is connected to the spring and to a plunger 63 that is slidable in a bearing 64 carried by a standard 65. The plunger carries a sprocket wheel 67 around which a chain 68 passes, the chain also passing around the sprocket 57 and a driving sprocket 69 that corresponds to 39 of Fig. 1.

When the driving stress exceeds a predetermined degree, the chain 68 will tend to straighten, thereby pulling the plunger 63 against the spring tension. A rack 71 carried by the plunger 63 meshes with a gear segment 72 that is mounted on a shaft 73 that carries a switch arm 74 for movement along terminals of a rheostat 77, to thereby vary the value of the current supplied to the motor. When the load on the grate is light and a small amount of current is required for proper motor speed, the parts will be in the position shown in Fig. 5. Upon slight increasein load, the arm will be moved to the next rheostat terminal and so on, as the load increases, thus supplying more power to the motor. The rheostat arm 74 is utilized also to break the circuit under overloads, simply by having it moved past the last terminal on the rheostat. At the limit of its clockwise movement the arm 74 will snap rearwardly and be held by insulation on the end of the member 77, at open-circuit position, thus keeping the motor deenergized until the arm is manually moved back to the face of 77. A Weighted lever at and a sprocket 79 maintain tension on the chain 68.

I claim as my invention:

1. The combination with a movably-mounted driven grate that is subject to varying load conditions, of an electric motor, a looped sprocket chain driven by the motor, a rotatable driving member driven by the chain, a second rotatable member, cushioning springs interposed between oppositely-disposed seating surfaces on the respective rotatable members, in position to transmit rotative movement from the first-named rotatable driving member to the second rotatable driving member, transmission mechanism that operatively connects the said second rotatable member to the said driven grate, an idler wheel in engagement with one run of the looped chain, a plunger in which the wheel is journaled, an adjustable spring that yieldably holds the plunger in position to yieldably maintain the said nm of the chain deflected, and an electrical control device that regulates the Value of current supplied to the motor, and is actuated through shifting of the plunger When the load on the said grate exceeds "a predetermined degree and straightens the said chain run from its deflected path toward a straight line.

2. Motor-driven apparatus as recited in claim 1, wherein the electrical control device is in the form of a rheostat having spaced terminals that are sequentially brought into the motor circuit by movement of the said plunger.

References Cited in the file of this patent UNITED STATES PATENTS Watson Nov. 4, 1902 Watson et a1 June 27, 1905 Wedge Aug. 18, 1922 Burns Apr. 6, 1926 Kant Jan. 29, 1935 Berg et a1 Mar. 8, 1935 Black et al July 18, 1935 Barnett Oct. 27, 1936 Drake Sept. 10, 1940 Jacobson et a1. Nov. 26, 1940 Lum Feb. 18, 1941 Merritt Oct. 9, 1956 

